Re: Maybe we can improve this function call-process-to-string?

[Eli Zaretskii <eliz@gnu.org>]

> Date: Thu, 8 Apr 2021 21:17:15 +0300
> From: Jean Louis <bugs@gnu.support>
> Cc: help-gnu-emacs@gnu.org
> 
> * Eli Zaretskii <eliz@gnu.org> [2021-04-08 19:30]:
> > So you actually need the numbers reported by those commands?  if so,
> > you can read them from the buffer into which the command's output is
> > stored, right?  You don't actually need the numbers in their string
> > form, right?
> 
> In that particular example numbers are just used as string, but
> sometimes I need numbers. That may not be most important. I do not
> understand your method of getting output from external command. 
> 
> How practically to do it?
> 
> I understood reading it from buffer is different than reading from
> shell-command-to-string.
> 
> Then to have output in buffer, I need call-process, but then again I
> need to enter that buffer and read string out of it.

You can use with-current-buffer for that.

> Again I have to use strings there.

Depends on what you want to do with that string.  My point is:
whatever you want to do with the string, do it with buffer text
instead.

> > > I would not know how to get output from system command by using those
> > > functions without using shell-command-to-string or call-process
> > 
> > You said buffer-substring doesn't take a buffer as an argument.  I'm
> > suggesting something like
> > 
> >   (with-current-buffer (get-buffer "foo")
> >     (buffer-substring ...))
> 
> That again comes back as a string, right?

Yes, but only because _you_ asked a buffer-substring.